Water pump pulley

[adem.csl]

I don't know if this is of any interest but euros do a smaller water pump pulley his could pump water round the system faster!!! Every little helps
9843

[Steve B]

Bigger the pulley the slower it turns so wouldn't this do the opposite??, or is my science GCSE not as good as I thought lol

[shane@mbtech]

It might make it seem quicker too :blalalala:

[shimmy]

It might make it seem quicker too :blalalala:

cnut

[adem.csl]

Sorry wrote larger meant smaller my bad!!
Won't make the car faster though lol

[alexk]

Can we find out the difference in the diameter ?

[adem.csl]

Can we find out the difference in the diameter ?

12cm and 13.3cm

[alexk]

12cm and 13.3cm

So 37.69cm circumference vs 41.78cm.

Therefore -> 10% higher rpm on the water pump which means 10% increased water flow.

It sounds good.
I am not very happy with the way they look though.
Is this how they really are (photos) ?

[shimmy]

Will the water pump be capable of surviving 10% highe from than it's supposed to run?

[uncle benz]

Show me some science that says rushing water through a radiator faster is better.

[shimmy]

Show me some science that says rushing water through a radiator faster is better.

i also was wondering

i suppose a bigger rad may mean the water has same time to cool then faster flow may nean extra cooling.

if the water is gettting less time to cool then benefit is questionable

[shane@mbtech]

i also was wondering

i suppose a bigger rad may mean the water has same time to cool then faster flow may nean extra cooling.

if the water is gettting less time to cool then benefit is questionable

Bigger cooler is more surface area.

Think of electric shower, put on full speed, warm water. Put on low speed, hot.

Think of rad as a reverse of this.

[uncle benz]

Bigger cooler is more surface area.

Think of electric shower, put on full speed, warm water. Put on low speed, hot.

Think of rad as a reverse of this.

Now I'm even more confused. The reverse of that you say...

So is that slow speed = warm, fast speed =hot

Or full speed = cool, low speed = cold.

To my mind there must be an optimum speed of coolant flow for a given size of radiator. Surely too slow will mean the coolant is cooled A LOT in the radiator, at the detriment of the coolant left in the engine which will peak much higher.
Too fast and it won't be cooled sufficiently by the radiator before being pushed back into the engine?
Where is the Gorilla when you need him???

[adem.csl]

So 37.69cm circumference vs 41.78cm.

Therefore -> 10% higher rpm on the water pump which means 10% increased water flow.

It sounds good.
I am not very happy with the way they look though.
Is this how they really are (photos) ?

What???? If one has a 12cm outer diameter and one has a 13.3cm diameter where did you get 37.69 and 41.78?
The pic is at the first post

I didn't say it would definitely work i was questioning would it make an improvement????

[shimmy]

What???? If one has a 12cm outer diameter and one has a 13.3cm diameter where did you get 37.69 and 41.78?
The pic is at the first post

I didn't say it would definitely work i was questioning would it make an improvement????

Alex was talking about circumference Adem, the distance around the edge. You'd quote diameter which is straight across the pulley.

Iirc circumference = 2x pie x diameter/2 = 2 x 3.142 x 12/2= 37.69 (I'm exhausted now)

[shane@mbtech]

Now I'm even more confused. The reverse of that you say...

So is that slow speed = warm, fast speed =hot

Or full speed = cool, low speed = cold.

To my mind there must be an optimum speed of coolant flow for a given size of radiator. Surely too slow will mean the coolant is cooled A LOT in the radiator, at the detriment of the coolant left in the engine which will peak much higher.
Too fast and it won't be cooled sufficiently by the radiator before being pushed back into the engine?
Where is the Gorilla when you need him???


It was more in response to shimmys quote about the time the coolant is in the radiator for.

If it's pushed through quicker then it's less likely to cool. That's why I likened it to electric shower, but opposite way round.

[uncle benz]

It was more in response to shimmys quote about the time the coolant is in the radiator for.

If it's pushed through quicker then it's less likely to cool. That's why I likened it to electric shower, but opposite way round.

Ahh, I get it now!

A bigger radiator has to be a better bet than messing with pulley sizes.

[shimmy]

It was more in response to shimmys quote about the time the coolant is in the radiator for.

If it's pushed through quicker then it's less likely to cool. That's why I likened it to electric shower, but opposite way round.

Yes, and I was saying (badly) that a bigger rad then will allow the water to cool more as it will stay in the rad longer even though it is flowing faster.

[Mike R]

Given how easy it is to reverse this, it should be very easy to test. Access the water temp menu so it is displayed in specific figures and carry out some measurements at a track day (noting ambient temp / barometric pressure changes through-out the day) and then repeat with the other pulley (even better if you can do this on the same day).

[adem.csl]

Alex was talking about circumference Adem, the distance around the edge. You'd quote diameter which is straight across the pulley.

Iirc circumference = 2x pie x diameter/2 = 2 x 3.142 x 12/2= 37.69 (I'm exhausted now)

Wicked cool im a monkey not a mathematician lol!
Thanks shimmy

[shimmy]

Wicked cool im a monkey not a mathematician lol!
Thanks shimmy

I had to get my daughter to explain to me first :-D

[_Nathan_]

I fitted underdrive pulleys to slow down the water pump (and alternator) and extend the life of those parts, wouldn't want either running faster!

[alexk]

I fitted underdrive pulleys to slow down the water pump (and alternator) and extend the life of those parts, wouldn't want either running faster!

Nathan is it not causing an issue to the cooling ? Slowing down the water pump ?

[_Nathan_]

Doesn't seem to be the case.

I actually wonder if the high speed of the water pump is causing cavitation at high RPM running on track?

[shimmy]

Doesn't seem to be the case.

I actually wonder if the high speed of the water pump is causing cavitation at high RPM running on track?

I had underdrive pulleys for a while, cant remember when but will check data and see if had overheating problems still with them in (def no problems at normal speeds or stopped)!!

[alexk]

Doesn't seem to be the case.

I actually wonder if the high speed of the water pump is causing cavitation at high RPM running on track?

Very interesting.

[shane@mbtech]

Doesn't seem to be the case.

I actually wonder if the high speed of the water pump is causing cavitation at high RPM running on track?

Another possible contributory factor maybe.

[alexk]

Another possible contributory factor maybe.

Very true, because as soon as you back off, the water temp drops immediately.

[shimmy]

Very true, because as soon as you back off, the water temp drops immediately.

Not convinced

My feeling is it is throttle related, not revs. I can be at full throttle but not full revs when the temps start to move

If it was water cavitation it would be caused when car runs at max revs, not max throttle/fueling

[shane@mbtech]

Not convinced

My feeling is it is throttle related, not revs. I can be at full throttle but not full revs when the temps start to move

If it was water cavitation it would be caused ephedra car runs at max revs, not max throttle/fueling

Is it that instantaneous?

[shimmy]

Is it that instantaneous?

It has to be hot and car heat soaked, oil then water temps finally rise when you are 100% throttle then within one or two corners they will drop until next time

It would be interesting to see if this is caused also when you run 100% throttle in another gear for a period (when air speed is lower)